Apparatus for obtaining alkaline cyanids.



No. 695,037. Patented Mar. ll, I902.

G. CRAlG.

APPARATUSFOR OBTAINING ALKALINE (.IYANIIJ S.

- (Application filed Jun. 9, 1901.) (No Nodal.)

3 Sheets-Shaet l;

No. 695,037. Patented. Mr. H, I902. a. cam.

APPARATUS FOR OBTAINING ALKALINE GYANIDS.

No. 695,037. Patented Mar. u, I902.

a. name.

APPARATUS FOR GBTAINING ALKALlNE GYANIDS.

(Application filed Jan. 2, 1901.)

(No Model.)

llnirnn Erarns Parent @lFFlQE.

GEORGE CRAIG, OF GLASGOW, SCOTLAND, ASSIGNOR TO ROBERT MORTON PATERSON, OF SPIERSFIELD, PAISLEY, SCOTLAND.

APPARATUS FOR OBTAlNING ALKALINE GYANlDS.

$PEUIFICATION forming part of Letters Patent No. 695,037, dated March 11, 1902. Application filed January 2, 1901. Serial No. 41,906. (No model.)

To all whom it may concern:

Be it known that I, GEORGE CRAIG, a subject of the Queen of Great Britain and lreland, and a resident of 9 Hampden Terrace, in the city of Glasgow, Scotland, have invented certain new and useful Apparatus for Obtaining Alkaline Oyanids, which invention is fully set forth in the following specification.

This invention has for its object to provide apparatus by means of which the obtainment of alkaline cyanids from crude materials containin g cyanogen according to the process described in the specification of the application for Letters Patent, No. 11,912, dated the 2d day of July, A. D. 1900, can be performed in a very efficient and ready manner.

According to this present invention there is provided an arrangement of furnace and adjuncts in which the crude material is dried and mixed and heated with the necessary agents and apparatus in which the materials are afterward subjected to continuous extraction by means of liquefied ammonia.

I will describe the invention with reference to the accompanying drawings.

Figure 1 is a longitudinal vertical section on the line 1 1,Fig. 3, of a furnace and adjuncts for use in drying, mixing, and heating the materials. fig. 2 is a transversesection on the line 3 3, Fig. 1. Figs. Sand 4 are horizontal sections, respectively, on the lines 2 2 and at 4-, Fig. 1. Fig. 5 represents an arrangement of apparatus wherein the prepared materials are subjected to treatment with liquefied ammonia.

The furnace A is constructed with two chambers B O through each of which passes a retortB O,provided with a screw-creeperI-l M or other propeller for passing the material through the said retorts. The first retort O is provided with a hopper G, by which the crude material (with, say, carbonate of soda) is fed into the said first retort, and the said first retort at its opposite end communicates with the second retort B by a passage in which is a mixer L, into which the agent to be added to the crude material is passed from a hopper L provided with an air-excluding arrangement, (indicated at 1,) so as to be thoroughly mixed therewith, the mixture being then passed along the second retort B and therefrom into a cooler N, which may be, like the retorts B O, provided with a screwcreeper N or other propeller and is situated outside the furnaceand provided with a cooling trough or jacket. The fireplace A is so arranged that the second retort B is first heated to the necessary temperature, and then the products of combustion pass through the ports D and around the first retort O to heat that retort sufficiently for drying or preheating, thence passing by the opening E to the chimney-flue F. The arrangements are such as to exclude air from the materials under treatment, and to insure this an inert gas may be passed into the retorts, mixing-chamher, and cooler. The arrangement described secures the continuity of the operation, so that the mixed material is introduced dry and hot into the decomposing-retort proper and 7c. thence is passed to the cooler without access of air. If oxid or carbonate of zinc with car bon or carbidbe employed as the agents, the arrangement may have two retorts O, the agents being preheated together in one retort 7 5 O to or near to incipient decomposition and the crude materials dried in the other retort O and the agents and crude materials passed together through the mixer and the retort B. In any'case there may, if desired, be more than one retortof each kind. The mixture thus prepared is then passed into extractor vessels,which may be vessels somewhat larger at top than at bottom and each with a perforated bottom and also aremovable perforated false bottom provided with a rod and eye or the like for removing it and the material upon it, or the said vessels may be provided with inner receptacles with perforated bottoms and perforated removable covers, forming bottom 0 and top filters, and with handles for removing them. They may, for example, be constructed as shown in section of one of them in Fig. 5. The outer vessel to is provided with a cover capable of being closed air-tightly and. with 5 a support for a perforated bottom g which may consist of two perforated disks provided with filter-cloths. These disks can be forced down tightly to the seat in the vessel by a screw bolt 1 passed through them and ICC through a stuffing-box in the bottom of the vessel and provided externally with a screw Above the top of the said rod and beneath the liquefied-ammonia outlet a seat is provided in the said vessel, and upon this seat upper perforated disks 1 with filter-cloths, rest. These disks 7 may be connected with the top cover, so as to make a tight joint with the seatfor example, by a telescopic con nection consisting of a tube 2 and a plunger 2, with a spring 2 between.

We will presume that the liquefied ammonia is to be passed upward through the charge. Beneath the perforated bottom of each extraction vessel 20' 10 w is a space into which opens an inlet for the liquefied ammonia passing from the reservoir u through the cook 6 pipe t, cocks a a a pipes d 01 CF, and cooks b 29 b leading from vessel to Vessel, and from the top of the last vessel in operation for the time being, the ammoniacal solution passing by one or other of the cocks c c 0 and pipes cl d 02 and cooks e l 6 6 and pipe 9 into the concentrator a. Each vessel w w w is also provided with valved openings at top and bottom for the expulsion and admission of air. Those for the expulsion of the air are in communication with an absorber for recovering any ammonia which may accompany the air, and they are marked 00, 00 and 00 The extraction vessels can be employed in any suitable number. We presume, in the case illustrated, that three such vessels are used; but the invention is not m m m are closed and the cock 1" is open) puts the pump 19 in communication with the concentrator n. Branch pipes provided with cocks f f f communicate from the pipes d d d with a pipe 72, provided with a cock h", through which ammoniacal solution can be drained from the vessels w w w into the concentrator 'n. The concentrator n communicates at bottom with the crystallizer o by the pipe n and cock n, and the said crystallizer can be put in communication with the pump 19 through the pipe 7' and cook a". It will therefore be seen that the said extractor vessels w 0 to are in connection with each other and wit-h the concentrator n and pump p, so that the liquefied ammonia can be passed through all or any of the said vessels to 1,0 'w as re quired, by manipulating the cooks, and so, also, that the ammoniacal cyanid solution can be passed through the said vessels as desired and from either of them into the concentrator n, and also so that the said extractor vessels, the concentrator, and the crystallizer can be put into connection with the vapor-pump p, as desired, to allow of the continuous workthrough absorbers, as aforesaid, to arrest ammonia. After the air has been expelled the outlet by which the air escaped is closed and the cooks adjusted for the washing of the charges with liquefied ammonia, the filtrate running through either or any or all of the extractor vessels and dissolving the alkaline cyanids from the charges therein and the solution passing through one or other of the pipes d, d (Z and g into the concentrator n, which is put in connection with the vapor-pump p to withdraw the ammonia for reuse in the process. Cyanid of ammonium produced during the am moniacal extraction may be removed from the liquefied ammonia by an occasional filtration through a waster containing caustic alkali or other suitable agent. The ammoniacally-moist residue left after the charge has been exhausted and the liquefied ammonia run off is freed from ammonia by isolating the vessel containing it from the ammonia-supply and putting it into suction connection with the vapor-pump p, and after exhaustion the cooks are manipulated so that the said vessel is put in connection with the ammonia-absorbers, and by opening the air-passages at top and bottom air is passed through the charge in the said vessel until all traces of ammonia are removed. The said extraction vessel is then opened and the spent charge removed and a fresh charge put in, all air expelled through the ammonia-absorbers, and the cooks manipulated so that this vessel is connected with the supply of liquefied ammonia as the last of the series, and so on with the other vessels, so that the process can be thus carried on continuously in series. A small quantity of the ammoniacal solution of cyanid can be run from the concentrator n continuously or at intervals into the crystallizer 0, (surrounded by a jacket o,) wherein it is evaporated to dryness by suction (it being put in communication with the pump 19 for the purpose) and heat, (which can be applied by water circulation admitted at o and passed out at o in the jacket o,) and when the receptacle 0 in this crystallizer becomes full of thoroughly-dried cyanid .it can be freed from ammonia by passing air in at o and out at 0 to the ammonia-absorber, and then it can be cut off from the rest of the apparatus by the cooks n r and be opened and the oyanid'receptacle 0 removed.

The concentrator preferably consists of a vessel n, with a connection which can be put IIO in communication b the cock t" with the vapor-pump p and with an inlet for the passage through the pipes g and 7t of the cyanid solution from the extractor vessels and an outlet through the GOCk/Il/ to the crystallizer 0, the said vessel 12 being surrounded by a vessel 3, (provided with an inlet and outlet 8 s for attemperating fiuid,) in which is a coil 3 in continuation of the pipes s and t for the removed ammonia and constituting a condenser which utilizes the cold produced by the evaporation in the concentrator.

Having now particularly described and ascertained the nature of the said invention and in what manner the same is to be performed, I declare that what I claim is- 1. In apparatus for obtaining alkaline cyanid from materials containing cyanogen by means of liquefied ammonia, an extractor in which the material is subjected to the action of liquefied ammonia, a concentrator communicating with the extractor and to which the ammonia solution passes from the latter, a crystallizer communicating with the concentrator, and a pump communicating with the concentrator and crystallizer for exhausting ammonia therefrom.

2. In apparatus for obtaining alkaline cyanid from material containing cyanogen by means of liquefied ammonia, an extractorin which the material is subjected to the action of liquefied an1monia,a concentrating-chainber communicating with the extractor, a condensersurrounding said concentrating-chamher, and a pump communicating with the upper part of the concentrating-chamber for withdrawing vaporized ammonia therefrom and with the condenser for forcing the vaporized ammonia therethrough.

3. In apparatus for obtaining alkaline cyanid from material containing cyanogen by means of liquefied ammonia, an extractor in which the material is subjected to the action of liquefied ammonia, a concentratonchamber communicating with the extractor and into which the ammonia solution passes from the latter-,a condenser about the concentrator, a crystallizer communicating with the co11- centrator, and a pump for exhausting ammonia from the concentrator and forcing it through the condenser.

4. In apparatus for obtaining alkaline cyanid from materials containing cyanogen by means of liquefied ammonia, a series of extractors in which the material is subjected to the action of liquefied ammonia, pipes connecting each extractor with its succeeding extractor and the last extractor of the group with the first extractor thereof, two valves in each connecting-pipe near the extractors respectively, a pipe having valved branches one communicating with each of the connecting-pipes at a point between one of the valves in the latter and one of the extractors to which it leads, an ammonia -supply pipe, branches leading therefrom to the connectingpipes respectively at points between the two valves of the latter, and a valve in each of said branches, whereby the ammonia solution may be passed through the extractors in series beginning with any desired extractor.

5. In apparatus for obtaining alkaline cyanid from materials containing cyanogen by means of liquefied ammonia, a series of extractors in which the material is subjected to the action of liquefied ammonia, pipes connecting each extractor with its succeeding extractor and the last extractor of the group with the first extractor thereof, two valves in each connecting-pipe near the extractors re spectively, a pipe having valved branches one communicating with each of the connecting-pipes at a point between one of the valves in the latter and one of the extractors to which it leads, an ammonia-supply pipe, branches leading therefrom to the connecting-pipes respectively at points between the two valves of the latter, a valve in each of said branches, whereby the ammonia may be passed through the extractors in series be ginning with any desired extractor, and an exhaust-pipe leading from each of the connecting-pipes.

6. In apparatus for obtaining alkaline cyanid from materials containing cyanogen by means of liquefied ammonia, a series of extractors in which the material is subjected to the action of liquefied ammonia, pipes connecting each extractor with its succeeding extractor and the last extractor of the group with the first extractor thereof, two valves in each connecting-pipe near the extractors respectively, a pipe having valved branches one communicating with each of theconnecting-pipes ata point between one of the valves in the latter and one of the extractors to which it leads, an ammonia supply pipe, branches leading therefrom to the connecting-pipes respectively at points between. the two valves of the latter, a valve in each of said branches, whereby the ammonia solution may be passed through the extractors in series beginning with any desired extractor, a concentrator, and exhaust-pipe connections leading from the extractors tovthe concentrator. i

7. In apparatus for obtaining alkaline cy anid from materials containing cyanogen by means of liquefied ammonia, a series of ex tractors in which the material is subjected to the action of liquefied ammonia, pipes connectin g each extractor with its succeeding extractor and the last extractor of the group with the first extractor thereof, two valves in each connecting-pipe near the extractors respectively, a pipe having valved branches one communicating with each of the connecting pipes at a.point between one of the valves in the latter and one of the extractors to which it leads, an ammonia-supply pipe, branches leading therefrom to the connecting-pipes rethrough the extractors in series beginning with any desired extractor, a combined concentrator and condenser, exhaust-pipe connections leading from the extractors to the concentrator part,and a pump connected with said part for withdrawing ammonia therefrom and forcing the same through the condenser part.

8. In apparatus for obtaining alkaline cyanid from materials containing cyanogen by means of liquefied ammonia, a series of extractors in which the material is subjected to the action of liquefied ammonia, pipes connecting each extractor with its succeeding extractor and the last extractor of the group with the first extractor thereof, two valvesin each connecting-pipe near the extractors respectively, a pipe having valved branches one communicating with each of the connectingpipes at a point between one of the valves in the latter and one of the extractors to which it 1eads,an ammonia-supply pipe,branc-hes lead ing therefrom to the connecting-pipes respectively at points between the two valves of the latter, exhaust-pipe connections leading from i the extractors to the concentrator part,-a crys= I tallizer and a pump connected with said part, a pipe leading from the pump to the condenser part, and a pipe leading from the crystallizer to the pump, whereby the pump withdraws ammonia from the concentrator part and the crystallizer and forces it through the condenser part.

9. In apparatus of the kind described, a pump, a crystallizer, a pipe connecting the pump and crystallizer, a combined concentrator and condenser comprising a concentrating vessel provided at its top with an inlet for ammoniacal cyanid solution and a pipe leading to the pump for drawing ofli' ammonia, and at its bottom with an outlet leading to the crystallizer, and a condensing-coil about the vessel connected with the pump.

In testimony whereof I have signed this specification in the presence of two subscrib ing witnesses.

GEORGE CRAIG. Witnesses:

DAVID JEFFREY, JOHN HARRISON. 

